MAGNETOELECTRIC NANOPARTICLES CONVERT SUBTHRESHOLD STATIC MAGNETIC FIELDS INTO ELECTRIC MODULATION OF CORTICAL NETWORK DYNAMICS

Weak static magnetic fields don’t directly modulate cortical activity, posing a fundamental limitation for non-invasive magnetic neuromodulation. Here we show that magnetoelectric nanoparticles (MENPs) convert such otherwise ineffective magnetic fields into functional neuromodulation at the network level in in vitro cortical slices.

Using extracellular local field potential recordings of spontaneous slow oscillations (Up/Down states), we first demonstrate that uniform DC magnetic fields (<100 mT) don’t alter oscillatory dynamics in the absence of MENPs. When the same static magnetic field is applied in the presence of MENPs, cortical dynamics change profoundly and reversibly: Down states shorten, oscillation frequency doubles, and Up state durations become polarity dependent. These effects closely match the canonical signature of weak DC electric field stimulation reported in cortical slice preparations [1, 2]. The polarity dependence further indicates an electric, rather than magnetic, origin of the modulation.

Our results demonstrate that MENPs render cortical networks magnetically addressable by converting subthreshold DC magnetic fields into effective electric neuromodulation. This work provides the first direct electrophysiological evidence that magnetoelectric transduction can control emergent cortical dynamics, opening a pathway toward wireless, polarity-controlled neuromodulation using static magnetic fields.

[1]D’Andola et al (2026) Journal of Physiology, in press.

[2] Covelo et al, Neuroscience (2025) 589: 109.